Quick note, the width and height tags are not necessary (or as far as I know, someone please correct me if I'm wrong), it displays the actual resolution of the image if neither is chosen.

For a guestbook, there are many choices. A quick google search will bring you to some. I can't really recommend one though. I do know that with Liway in your cPanel there is a section of free CGI scripts that will basically install for you and a guestbook is one of those scripts. So go look at that as well.